Diagnostic method and system for detecting early age macular degeneration, maculopathies and cystoid macular edema post cataract surgery

ABSTRACT

A retinoscopic device, technique and scale for estimating the reflectance of the macula pigment optical density (MPOD) in normal and abnormal eyes in order to detect early pathology of the retinal pigment epithelium and photoreceptors thus screening for macular pathology the most prevalent of which is Age-related Macular Degeneration (AMD) and retinal edema and cystoid macular edema post cataract surgery.

FIELD OF THE INVENTION

This invention relates to a method and system for using a calibratedretinoscope and parallel light technique to estimate the reflection ofmelanin particles in the retina to detect macular degeneration prior tophysical symptoms.

BACKGROUND OF THE INVENTION

In the Western world, maculopathy or AMD is the leading cause ofblindness in the elderly population and affects 10%-13% of adults over65 in North America, Europe, Australia and Asia In 2012 the undiagnosedprevalence of AMD in the USA was estimated to be 2.3 million. Estimatesof the global cost due to AMD are US$343 billion with US$255 billion indirect health care costs.

According to the International Classification age-related maculopathy(ARM) is a degenerative disease of the macula characterized in the earlystage by large, soft yellow drusens, hyper-/hypopigmentation of theretinal pigment epithelium (RPE), and a moderate loss of central vision(age-related maculopathy). Age related maculopathy disease (AMD) is alate stage of ARM. Dry AMD refers to geographic atrophy and wet AMD ischaracterized by choroidal neovascularization (CNV), detachment of theRPE, subretinal hemorrhage or retinal scarring.

Currently, several AMD classification schemes, grading systems, andseverity scales have been developed in an effort to provide standards toassist clinicians and researchers in the diagnosis and management ofthis important disorder. The most current clinical classification of AMDtakes in consideration pigment abnormalities and is illustrated in FIG.16.

It is believed the ultimate therapy for AMD will lie in the preclinicalidentification of those who are genetically “at risk” for the diseaseand treatment with genetically specific supplements. At the presenttime, AMD is initially diagnosed by an ophthalmologist or optometristwith a fundus examination and Amsler grid of patients who complain of adecrease in their vision. The hallmarks of early AMD are yellow drusensand pigment abnormalities (hypo and hyperpigmentation) of the retinalpigment epithelium (RPE) which occur after the onset of the AMD process.AMD is characterized by a degeneration of the retinal pigment epitheliumand photoreceptors (rod and cones) and a thickening of the Bruch'smembrane in the macula.

The early detection of AMR could reduce the growing societal burden bytargeting and emphasizing modifiable habits earlier in life. Withgenetic testing antioxidants and other supplements specific to thepatient's genotype can be recommended. More frequent examinations ofthose at high risk due to family history or signs of early orintermediate disease would be beneficial.

It is believed that the pigmentary changes observed in the macula of AMDeyes are attributable to degenerative changes in the highly melanizedRPE cells because most of the early clinical signs and histopathologicalchanges have been localized to this cell layer. It has been suggestedthat melanin in the retinal pigment epithelium (RPE) and choroid mayprotect the macular region by its antioxidant capability and itscapability to attenuate or reflect light thereby decreasingphotochemical light damage.

In retinoscopy, a light is shone into a patient's eye and the reflected“streak” of light is used to estimate the correction of a patient'srefractive error. The results are then the beginning point for arefraction. However, with the calibrated retinoscope and this technique,the brightness of the reflected beam is dependent on the health of thepigment epithelium and thus gives an early indication of macularpathology. This calibrated diagnostic retinoscope and technique allowthe general ophthalmic physician to detect early and late stages of thedestruction of the retinal pigment epithelium in AMD. The commondenominator between AMD and the pupillary reflex in retinoscopy lies inthe melanin pigment particles of the microvilli of the retinal pigmentepithelium (RPE) which surrounds the photoreceptors, the choroid and/orthe outer segment of the cones.

In 1926, Jacob C Copeland designed a retinoscope (U.S. Pat. No.3,597,051) and a technique of retinoscopy which has since been taught tooptometrists and ophthalmologists for obtaining an objective measurementof the refractive error of patient's eyes for spectacles and/or contactlenses. All retinoscopes have been based upon on his work.

Originally, Copeland's and other retinoscopes used diverging light andspots of light to estimate the refractive error. Copeland introducedstreak retinoscopy in the US and it was rapidly accepted because it madedetermination of the axis of astigmatism more precise. The technique wasreferred to as “streak retinoscopy” because a streak of reflected light,or the pupillary reflex, was produced during the technique.

In 1968, Copeland and Walter M. Lewis designed the Copeland Optec 360Streak Retinoscope, U.S. Pat. No. 3,597,051 (as illustrated in FIG. 17).This retinoscope contains a +20.00 D condensing lens and a bi-pinfilament bulb. When the thumb-slide is in its upper position, thefilament of the lamp is less than five centimeters from the condensinglens and the rays emanating from the filament and passing out of thecondensing lens are diverging. Moving the thumb-slide to a lowerposition causes the light rays to converge. When the filament is at thefocal point of the +20.00 D lens or approximately 5 cm from the +20.00 Dlens, the light rays are parallel.

Sims' calibrated refractive retinoscopic techniques uses convergingrather than diverging light. The Sims' retinoscope can also be used forcalibrated diverging or conventional diverging retinoscopic techniques.It has been modified so that auxiliary lenses can be attached to theback of the head of the retinoscope to place the examiner's eye in focuswith the patient's pupillary plane in order to have an identical(conjugate) image of the pupillary reflex. Parallel light is used afterthe refractive error has been determined to judge the streak on areflectance scale 1 (very poor and difuse) to 5 (brilliant).

In conventional retinoscopy, the pupillary reflex cannot be used toevaluate the melanin reflectance. The endpoint of conventionalretinoscopy is an infinity neutrality reflex which fills the pupil andthere is no streak. The width of the reflected retinoscopic light fromthe reflecting membrane spans an area much larger than the size of thepupil and is enormous, making it impossible to evaluate the reflectanceof the macular pigment (MP). With conventional retinoscopy, therefractive error is initially determined by under correcting therefractive error to create a visible with-motion pupillary streak reflexthat expands and moves at an exponentially increasing speed asneutrality is reached. These exponential changes of the with-motionstreak makes it impossible to evaluate the reflectance of the MP.

Production of the Pupillary Reflex:

The cones act as an optical waveguide for visible light due to theirtubular structure and the index gradient between the cell wall andinternal medium. Since the cone's receptors are tightly packed, they actas a “fiber optic plate” extending from the external limiting membraneto the pigment epithelium (as illustrated in FIG. 18). Therefore light,that strikes the outer limiting membrane located at the openings of thephotoreceptors, is transmitted to the photosensitive pigment in theouter segments by a waveguide mechanism and then reflected to the outerlimiting membrane.

The reflected light from the retina pigment epithelium (RPE) interfaceappears to be due to Fresnel reflection from the melanin granules withinthe melanosomes in the RPE. A Fresnel reflection is a reflection oflight on a planar interface between two homogeneous media havingdifferent refractive indices. The melanin granules in the pigmentepithelium have a high index of refraction compared to the surroundingtissue. The reflected light then reenters the photoreceptors andtransmitted to the external limiting membrane (ELM) and pupil. The ELMis considered the effective ocular reflecting surface for visible lightin the performance of retinoscopy or photorefraction. Conventionally,the pupillary reflex is used to measure or estimate a refractive error,not to evaluate the reflectance from the melanin pigment.

Macular Degeneration and Reflectance:

Most of the early clinical signs and histopathological changes have beenlocalized to the pigment epithelium. It is believed that it is themelanin in the retinal pigment epithelium (RPE) and choroid whichprotects the macular region through its antioxidant capability and itscapability to attenuate blur light thereby decreasing photochemicallight damage. Healthy pigment epithelium is more reflective than thatwhich is damaged and when evaluated produces a brilliant to clearstreak.

The calibrated retinoscope and diagnostic technique described in thispatent application allows the average ophthalmic physician to detectearly and late stages of the destruction of the retinal pigmentepithelium in AMD.

The relevant prior art includes the following references:

Pat. No. Inventor Issue/Publication Date 3,597,051 Copeland Aug. 3, 19715,430,508 Sims Jul. 4, 1995 5,500,698 Sims Mar. 19, 1996 5,632,282 Hayet al. May 27, 1997 5,650,839 Sims Jul. 22, 1997 6,578,965 Grant Jun.17, 2003 6,640,124 Elsner et al. Oct. 28, 2003 2008/0221416 Baker Sep.11, 2008 7,467,870 van de Kraats et al. Dec. 23, 2008 8,272,739 SimsSep. 25, 2012 8,272,740 Sims Sep. 25, 2012 8,485,664 Rowe Jul. 16, 20132014/0140112 Lashkari May 1, 2014 CN202458313 Zhang Oct. 3, 2012(Non-Patent Literature)

-   Ferris, F L III, Wilkinson, C P, Bird A, et al. CLINIAL    CALSSIFICATION OF AGE-RELATED MACULAR DEBENERAITON. Ophthalmology,    2012, 844-851 Beatty S, Boulton M, Henson D, Koh H H, Murray I    J (1999) Macular pigment and age related macular degeneration. Br J    Ophthalmol 83:867-77

SUMMARY OF THE INVENTION

The primary object of the present invention is to improve the detectionof age-related maculopathies (ARM & AMD) other maculopathies and cystoidmacular edema post cataract surgery using a modified retinoscope.

An additional object of the present invention is to provide aretinoscope capable of performing several calibrated refractive anddiagnostic retinoscopic techniques and conventional retinoscopy.

The present invention fulfills the above and other objects by providinga retinoscopic device, technique and scale for estimating thereflectance of the macula pigment optical density (MPOD) in normal andabnormal eyes in order to detect early pathology of the retinal pigmentepithelium and photoreceptors thus screening for macular pathology, themost prevalent of which is Age-related Macular Degeneration (AMD).

The above and other objects, features and advantages of the presentinvention should become even more readily apparent to those skilled inthe art upon a reading of the following detailed description inconjunction with the drawings wherein there is shown and describedillustrative embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed description, reference will be made to theattached drawings in which:

FIG. 1 is a side partial cutaway view of a condensing lens, a mirror, alamp, a power capsule with a knurl for rotating the power capsule and athumb-slide which moves the power capsule housing the lamp;

FIG. 2 is a schematic of the knurl area on the power capsule with acircumferential line;

FIG. 3 is a schematic view of light rays emanating from a retinoscope ina diverging pattern;

FIG. 4 is a schematic view of light rays emanating from a retinoscope ina converging pattern;

FIG. 5 is a flow chart for optically measuring one's retinoscopicworking distance;

FIG. 6 is a chart for calibrating the retinoscope using diverging raysfor an infinity retinoscopic and +0.50 D endpoints and for calibrating aretinoscope using converging rays for +0.50 D and +0.75 D retinoscopicendpoints;

FIG. 7-A is an attachable plate for retrofitting a retinoscope for a+0.50 D retinoscopic endpoint using converging rays calibrated to theexaminer's retinoscopic working distance;

FIG. 7-B is an attachable plate for retrofitting a retinoscope for a+0.75 D retinoscopic endpoint using converging rays calibrated to theexaminer's retinoscopic working distance;

FIG. 7-C is an attachable plate for retrofitting a retinoscope for aninfinity retinoscopic endpoint using diverging rays calibrated to theexaminer's retinoscopic working distance;

FIG. 7-D is an attachable plate for retrofitting a retinoscope for a+0.50 D retinoscopic endpoint using diverging rays calibrated to theexaminer's retinoscopic working distance;

FIG. 8 is a flow chart showing the steps for calibrating a retinoscopefor a +0.50 D retinoscopic endpoint using converging retinoscopic lightrays calibrated to the examiner's retinoscopic working distance;

FIG. 8-A is a retinoscope showing proper attachment of the +0.50 Dconverging plate after calibration of retinoscope light rays to theexaminer's retinoscopic working distance;

FIG. 9 is a flow chart showing the steps for calibrating a retinoscopefor a +0.75 D pupillary reflex endpoint using converging retinoscopiclight rays;

FIG. 9-A is a retinoscope showing proper attachment of the +0.75 Dconverging plate after calibration of retinoscopic light rays to theexaminer's retinoscopic working distance;

FIG. 10 is a flow chart showing the steps for calibrating a retinoscopefor an infinity retinoscopic endpoint using diverging retinoscopic lightrays calibrated to the examiner's retinoscopic working distance;

FIG. 10-A is a retinoscope showing proper attachment of the infinitydiverging plate after calibration of the retinoscopic light rays to theexaminer's retinoscopic working distance;

FIG. 11 is a flow chart showing the steps for calibrating a retinoscopefor a +0.50 D retinoscopic endpoint using diverging retinoscopic lightrays calibrated to the examiner's retinoscopic working distance;

FIG. 11-A is a retinoscope showing the proper attachment of the +0.50 Ddiverging plate after calibration of retinoscopic light rays to theexaminer's retinoscopic working distance;

FIG. 12 is a flow chart showing the steps for performing a calibrationcheck of a retinoscope emanating converging rays calibrated to theexaminer's retinoscopic working distance;

FIG. 13 is a rear view of a retinoscope showing a slide bar which can beadjusted to maintain the thumb-slide in a fixed position to maintain thecalibration of the retinoscope for future retinoscopies;

FIG. 14 is a side view of a retinoscope showing a slide bars which canbe adjusted to maintain the thumb-slide in a fixed position to maintainthe calibration of the retinoscope for future retinoscopies;

FIG. 15 is a front perspective view of a bulb extender of the presentinvention; and

FIG. 16 is a chart showing the clinical classification of age-relatedmacular debeneraiton;

FIG. 17 is a side view of a retinoscope of the prior art,

FIG. 18 is an illustration of histology of the macula with pigmentepithelium;

FIG. 19A is a side view of a retinoscope calibrated to emit parallellight rays to make the streak pupillary reflex image and the image seenby the examiner conjugate;

FIG. 19B is a side view of a retinoscope calibrated for convergingretinoscopy with a +0.50 D pupillary streak endpoint and parallelretinoscopy for the detection of age-related maculopathies;

FIG. 19C is a side view of a retinoscope calibrated for convergingretinoscopy with a +0.75 D pupillary streak endpoint and parallelretinoscopy for the detection of age-related maculopathies;

FIG. 19D is a side view of a retinoscope calibrated for divergingretinoscopy with a +0.50 D pupillary streak endpoint and parallelretinoscopy for the detection of age-related maculopathies;

FIG. 19E is a side view of a retinoscope calibrated for divergingretinoscopy with an infinity neutrality pupillary endpoint and parallelretinoscopy for the detection of age-related maculopathies and havingslide locks above and below the thumb slide to allow the examiner tochange the divergence or convergence of the retinoscopic light toparallel light rays without moving the retinoscope;

FIG. 20A is an illustration of an extrapolated focal point (Image I₃)behind a retina when the retinoscopic light is parallel (Image I₁=0.00D);

FIG. 20B is an illustration of a reflected pupillary image (Image I₃)focused to a hole in a mirror with the examiner seeing a reflectedstreak pupillary image (Image I₃) as a conjugate image;

FIG. 21 is a side view of a retinoscope calibrated to emit parallellight and an attachable emblem having a parallel light line attached tothe slide plate after calibration of the retinoscope; and

FIG. 22 is a chart illustrating the luminance of the calibratedpupillary streak graded on a scale of 1-5 used to evaluate the severityof the age-related maculopathy or degeneration (AMD).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIG. 1, a side partial cutaway view of a retinoscope 1having a thumb-slide 2 and a condensing lens 3 and a lamp 4 is shown.The lamp 4 includes a linear filament 5 designed to create a “streak”image which is reflected from a patient's retina and seen by apractitioner, such as an optometrist or ophthalmologist. The thumb-slide2 moves the power capsule housing the lamp 4 moves up and down along ahandle of the retinoscope 6 so that when the thumb-slide 2 is in amaximal upward position, the filament 5 is less than 5 cm from lens 3which has an approximate power of +20.00 D. When the thumb-slide 2 is ina maximal down position, the filament 5 is approximately 6.6 cm from thelamp 4. The practitioner can view the light rays reflected from thepatient's retina through a small openings 7 in mirror 8 and head ofretinoscope. The examiner can only see the retinoscopic light on thepatient's iris and the reflected pupillary reflex. The examinernevertheless is able to move the pupillary reflex toward neutralizationby the movement and orientation of the pupillary reflex. The examinerdraws all of the retinoscopic signals from the pupillary reflex, thatis, when to change or rotate the retinoscopic streak to achieveneutralization of the spherical and cylindrical error.

With reference to FIG. 2, calibration of the retinoscope requires acalibration line 11 in the knurl area 9 on the power capsule 10 to alignthe Plates 7A and 7B for converging infinity retinoscopy and Plates 7Cand 7D for diverging retinoscopy after the retinoscope is calibrated tothe specifications in the Calibration Chart 18.

With reference to FIG. 3, a schematic view of light rays 12 emanatingfrom a retinoscope 1 in a diverging pattern 13 is shown. In divergingretinoscopy the lamp 4 is within the focal length of lens 3. Theproximity of the lamp 4 to the lens 3 causes the light rays 12 emittedfrom the retinoscope 1 to spread out into a diverging pattern 13. Theretinoscopic technique of identifying and neutralizing a refractiveerror is the same with calibrated diverging retinoscopy as withconventional retinoscopy. Calibrated diverging retinoscopy differs fromconventional retinoscopy in that the divergence of the emittedretinoscopic light rays 12 is calibrated to a fogging lens whose focallength is equal to one's retinoscopic working distance. The endpoint ofcalibrated diverging retinoscopy can be an infinity retinoscopicendpoint which is identical to the endpoint of conventional retinoscopyor a +0.50 D with-motion pupillary reflex.

With reference to FIG. 4, a schematic view of light rays 12 emanatingfrom a retinoscope 1 in a converging pattern 14 is shown. In convergingretinoscopy, the lamp 4 is displaced beyond the focal length of lens 3.The increased distance of the lamp 4 from the lens 3 causes the lightrays 12 emitted from the retinoscope 1 to focus into a convergingpattern 14.

With reference to FIG. 5, a flow chart showing the steps for measuring aretinoscopic working distance for use in calibrating a retinoscope forconverging and diverging retinoscopy is shown. The examiner'sretinoscopic working distance is optically measured by focusing theretinoscopic light into an emmetropic eye using the thumb slide until aneutrality reflex occurs 15. Then, the retinoscopist holds thethumb-slide on the retinoscope in place and the emitted retinoscopiclight is focused onto a wall by moving the retinoscope towards the walluntil the streak is in focus 16. Finally, the distance between the walland retinoscope is measured to obtain the examiner's retinoscopicworking distance 17.

With reference to FIG. 6, a calibration chart 18 is shown. Thecalibration chart 18 lists the retinoscopic working distance incentimeters 19 and the required power of the calibration lens to be heldin front of the retinoscope, which is displaced from a wall a distanceequal to the examiner's retinoscopic working distance 19, in order tocalibrated the diverging retinoscopic light for an infinity endpoint 20and a +0.50 D endpoint 21. Chart 18 also lists the distance aretinoscope must be held from a wall to calibrated the retinoscope usingconverging light for a +0.50 D endpoint 22 and a +0.75 D endpoint 23,when performing retinoscopy from one's retinoscopic working distance.

With reference to FIG. 7-A, an attachable plate 24 for retrofitting aretinoscope 1 when calibrated for a +0.50 D with-motion endpointpupillary reflex using converging rays 14 emitted from the retinoscope 1is shown. The plate 24 shown here is a +0.50 D converging plate 25 andis used when the converging light emanating from the retinoscopies iscalibrated for a +0.50 D with-motion retinoscopic endpoint, as shownfurther in FIG. 8. The +0.50 D converging plate 25 has a front surface26, a rear surface 27 and an alignment line 28. The plate 24 isattachable to the retinoscope via an attachment means 29, such as screwsnuts, etc. The plate 24 is moveable via an adjustment means 30, such asa slot that moves along a screw, so that a user may adjust the alignmentline 28 up or down to be in alignment with the calibration line 11 onthe power capsule 10. After the retinoscope is calibrated and plate 24secured into position, the alignment line 28 on plate 24 allows theretinoscopist to know where to place the calibration line 11 on thepower capsule 10 to obtain a +0.50 D retinoscopic endpoint usingconverging light, as shown further in FIG. 8-A.

With reference to FIG. 7-B, an attachable plate 24 for retrofitting aretinoscope 1 when calibrated for a +0.75 D with-motion retinoscopicreflex using converging light rays 14 emitted from the retinoscope 1 isshown. The plate 24 shown here is a +0.75 D converging plate 31 and isused when the converging light 14 emanating from the retinoscope iscalibrated for a +0.75 D with-motion retinoscopic endpoint, as shownfurther in FIG. 9. The +0.75 D converging plate 31 has a front surface26, a rear surface 27 and an alignment line 28. The plate 24 isattachable to the retinoscope via an attachment means 29, such as screwsnuts, etc. The plate 24 is moveable via an adjustment means 30, such asa slot that moves along a screw, so that a user may adjust the alignmentline 28 up or down to be in level with the calibration line 11 on thepower capsule 10. After the retinoscope is calibrated and plate 24secured into position, the alignment line 28 on plate 31 allows theretinoscopist to know where to place the calibration line 11 on thepower capsule 10 to obtain a +0.75 D retinoscopic endpoint usingconverging light, as shown further in FIG. 9-A.

With reference to FIG. 7-C, an attachable plate 24 for retrofitting aretinoscope 1 when calibrated for an infinity endpoint using diverginglight rays 13 emitted from the retinoscope 1 is shown. The plate 24shown here is an infinity endpoint diverging plate 32 and is used whenthe diverging light 13 emitted from the retinoscope is calibrated for aninfinity retinoscopic endpoint, as shown further in FIG. 10. Theinfinity diverging plate 32 has a front surface 26, a rear surface 27and an alignment line 28. The plate 24 is attachable to the retinoscopevia an attachment means 29 such as screws, adhesive, nuts, etc. Theplate 24 is moveable via an adjustment means 30, such as a slot thatmoves along a screw, so that a user may adjust the alignment line 28 upor down to be level with the calibration line 11 on the power capsule 10after the retinoscope is calibrated. After the retinoscope is calibratedand plate 32 secured into position, the alignment line 28 on plate 32allows the retinoscopist to know where to place the calibration line 11on the power capsule 10 to perform retinoscopy with diverging light raysto obtain an infinity retinoscopic endpoint adjusted to one retinoscopicworking distance as shown further in FIG. 10-A.

With reference to FIG. 7-D, an attachable plate 24 for retrofitting aretinoscope 1 when calibrated to a +0.50 D with-motion pupillary reflexendpoint using diverging retinoscopic light rays 13 is shown. The plate24 shown here is a diverging plate 33 and is used when the diverginglight emanating from the retinoscope is calibrated for a +0.50 D withmotion retinoscopic endpoint as shown further in FIG. 11. The +0.50 Ddiverging plate 33 has a front surface 26, a rear surface 27 and analignment line 28. The plate 24 is attachable to the retinoscope via anattachment means 29, such as screws, adhesive, nuts, etc. The plate 24is moveable via an adjustment means 30, such as a slot that moves alonga screw, so that a user may adjust the alignment line 28 up or down tobe in alignment with the calibration line 11 on the power capsule 10after the retinoscope is calibrated. The alignment line 28 on plate 33allows the retinoscopist to know where to place the calibration line 11on the power capsule 10 to perform retinoscopy with diverging light raysto obtain a +0.50 D retinoscopic endpoint adjusted to one retinoscopicworking distance as shown further in FIG. 11-A.

With reference to FIG. 8, a flow chart showing the steps for calibratinga retinoscope for a +0.50 D with-motions retinoscopic endpoint usingconverging retinoscope light rays 14 is show. First, the retinoscopicworking distance is optically measured 34 as shown in FIG. 5. Then, therequired focal length of the emitted retinoscope light for a +0.50 Dretinoscopic endpoint is determined 35 using the calibration chart 18illustrated in FIG. 6. For example, if the retinoscopic working distanceis 67 cm, the required focal length of the emitted retinoscopic light is100 cm. Next, the retinoscope is placed at the proper focal length froma wall 36 and focused 37. Finally 38, the alignment line 28 on the +0.50D converging plate 25 is aligned with the calibration line 11 on thepower capsule 10 as shown further in FIG. 8-A and secured 39.

With reference to FIG. 8-A, a retinoscope 1 having a +0.50 D convergingplate 25 attached thereto is shown. The retinoscope 1 has beencalibrated for a +0.50 D pupillary reflex endpoint using convergingretinoscope light rays 14. The technique for performing retinoscopeusing a retinoscope calibrated for a +0.50 D retinoscopic endpoint isthe same as in conventional retinoscopy, except that the calibrationline 11 on the power capsule 10 is aligned with the alignment line 28 onthe +050 D converging plate 25 and the retinoscopic endpoint is a +0.50D with-motion retinoscopic reflex with the +0.50 D pupillary reflex andintercept moving in unison.

With reference to FIG. 9, a flow chart showing the steps for calibratinga retinoscope for a +0.75 D with-motions retinoscopic endpoint usingconverging retinoscope light rays 14 is show. First, the retinoscopicworking distance is measured 34 as shown in FIG. 5. Then, the requiredfocal length of the emitted retinoscope light is determined 35 using thecalibration chart 18 illustrated in FIG. 6. For example, if theretinoscopic working distance is 67 cm, the required focal length of theemitted retinoscopic light is 133 cm. Next, the retinoscope is placed atthe proper focal length from a wall 36 and focused 37 and thethumb-slide held in position. Finally 38, the alignment line 28 on the+0.75 D converging plate 31 is aligned with the calibration line 11 onthe power capsule 10 of retinoscope 1 as shown further in FIG. 8-A andsecured 40.

With reference to FIG. 9-A, a retinoscope 1 having a +0.75 D convergingplate 31 attached thereto is shown. The retinoscope 1 has beencalibrated for a +0.75 D endpoint using converging retinoscopic lightrays 14. The technique for performing retinoscopy using a retinoscopecalibrated for a +0.75 D retinoscopic endpoint is the same as inconventional retinoscopy, except the calibration line 11 on powercapsule 10 is aligned with the alignment line 28 on the +075 Dconverging plate 31 and the retinoscopic endpoint is a +0.75 Dretinoscopic and moves in unison with the intercept.

With reference to FIG. 10, a flow chart showing the steps forcalibrating a retinoscope 1 for an infinity retinoscopic endpoint usingdiverging retinoscopic rays 13 is shown. First, the retinoscopic workingdistance 34 is measured in centimeters, as shown in FIG. 5. Next 41, theretinoscopic working distance in centimeters 19 is matched to the powerof the calibration lens required 20 using the calibration chart 18. Forexample, if the retinoscopic working distance is 67 cm, the power ofcalibration sphere would be +3.00 D. Next, the retinoscope 1 is placedat a distance from the wall equal to the retinoscopic working distance42. Next, the +3.00 D calibration sphere as determined from 41 is placedin front of the retinoscope 43. With the thumb-slide 2 in the maximalupward position and the diverging retinoscopic light shinning throughthe +3.00 D calibration spherical lens, the thumb-slide 2 is lowereduntil the retinoscopic streak is focused onto the wall 37. If theretinoscopic streak fails to focus onto the wall, the bulb 4 is advancedtowards the condensing lens 3 within the retinoscope 1 and the procedurerepeated until the retinoscopic streak is focused onto the wall, 44.Next 45, the alignment line 28 on the infinity diverging plate 32 isaligned with the calibration line 11 on the power capsule 10 and securedin position 46 as shown further in FIG. 10-A.

With reference to FIG. 10-A, a retinoscope 1 having a diverging plate 32attached thereto is shown. The retinoscope 1 has been calibrated for aninfinity retinoscopic endpoint using diverging retinoscope light rays13. The technique for performing retinoscopy using an infinityretinoscopic endpoint with the emitted retinoscopic light rayscalibrated to the examiner's retinoscopic working distance is the sameas in conventional retinoscopy, except that the calibration line 11 onthe power capsule 10 is aligned with the measuring line 28 on theinfinity plate 32.

With reference to FIG. 11, a flow chart showing the steps forcalibrating a retinoscope 1 for a +0.50 D retinoscopic endpoint usingdiverging retinoscope light rays 13 is show. First the working distanceis measure centimeters 34, as shown in FIG. 5. Next 41, the retinoscopicworking distance in centimeters 19 is matched to the power of thecalibration lens required 21 using the calibration chart 18. Forexample, if the retinoscopic working distance is 67 cm the power of thecalibration sphere would be +3.50 D. Next, the retinoscope 1 is placedat a distance from the wall equal to the retinoscopic working distance42. Next, the +3.50 D sphere is placed in front of the retinoscope 43.With the thumb-slide 2 in the maximal upward position and the divergingretinoscopic light shinning through the +3.50 D calibration lens, thethumb-slide 2 is lowered until the retinoscopic streak is focused ontothe wall 37. If the retinoscopic streak fails to focus onto the wall,the bulb 4 is displaced toward the +20 D condensing lens 3 within theretinoscope and the procedure repeated until the retinoscopic streak isfocused onto the wall, 44. Next 47, the alignment line 28 on +0.50 Ddiverging plate 33 is aligned with the calibration line 11 on the powercapsule 10 and secured in position 48 as shown further in FIG. 11-A.

With reference to FIG. 11-A, a retinoscope 1 having a +0.50 D divergingplate 33 attached thereto is shown. The retinoscope 1 has beencalibrated for a +0.50 D retinoscopic endpoint using diverging lightrays 13 exiting the retinoscope. The technique for performingretinoscopy using a retinoscope calibrated to one's retinoscopic workingdistance for a +0.50 D retinoscopic endpoint is the same as conventionalretinoscopy except the retinoscopic endpoint is a +0.50 D with-motionretinoscopic endpoint and the calibration line 11 is aligned with thealignment line 28. In contrast to the +0.50 D retinoscopic endpointproduced with converging rays emitted from the retinoscope in FIG. 8-A,with diverging rays the +0.50 D retinoscopic endpoint moves faster thanthe intercept.

With reference to FIG. 12, a flow chart showing the steps for performinga calibration check on retinoscopes calibrated to emit converging rays14 as shown in FIGS. 8-A and 9-A is shown. First, the practitionerassumes his or her routine retinoscope distance 49. Then thepractitioner lowers the thumb-slide 2 of the retinoscope from itsmaximal upward position until a neutrality reflex is seen in anemmetropic eye 12 and holds the thumb-slide in this position 15. If thecalibration line 11 on the power capsule 10 is level with the alignmentline 28 on the converging plates 25 or 31, the retinoscope is calibrated50. In the Copeland Optec 360 Streak Retinoscope, the thumb-side is keptin the most superior position by a spring.

With reference to FIGS. 13 and 14, a rear view and a side view,respectively, of a retinoscope 1 having an upper slide bar 51 attachedto the body of the retinoscope and located superiorly to the thumb-slide2 thereto and having a lower slide bar 56 attached to the body of theretinoscope and located inferiorly to the thumb-slide 2 is shown. Theslide bars 51, 56 are attachable to the retinoscope via an attachmentmeans 29, such as screws, nut, etc. The slide bars 51, 56 are moveablevia an adjustment means 30, such as a slot that moves along a post 54.After the retinoscope is calibrated, the slide bars 51, 56 are adjustedto touch the top and bottom, respectively, of the thumb-slide 2 andlocked in place via a locking means 55, such as a screw, etc., toprevent the thumb-slide 2 from moving upward or downward.

Although a practitioner may use a +0.50 D retinoscopic endpoint or a+0.75 D retinoscopic endpoint, the +0.50 D retinoscopic endpoint iseasier, faster and more convenient to confirm than the +0.75 Dretinoscopic endpoint, since during retinoscopy, the neutrality reflexis displaced 2 lenses from the +0.50 D retinoscopic endpoint and 3lenses from the +0.75 D retinoscopic endpoint.Finally with reference to FIG. 15, a front perspective view of a bulbextender 52 of the present invention is shown. The bulb extender 52 actsas a spacer to increase the height of a lamp 4 and filament 5 within theretinoscope 1. The bulb extender 52 elevates lamps 4 having shorterfilaments 5 towards the lens 3 in order to increase the divergence ofemitted retinscopic light. The bulb extender 52 has at least oneaperture 53 to allow electronic communication between a power source ofthe retinoscope 1 and the filament 5.

With reference to FIGS. 19A-22, the measurement of the reflectance ofthe MPOD is preferably performed with a modified Copeland Optec 360Streak Retinoscope, with a halogen or incandescence bulb with a linearfilament and an elongated permanent or attachable head rest, asillustrated in FIG. 19A projecting parallel light rays. The thumb-slidemoves the bulb in relation to a +20.0 D spherical lens within theretinoscope to emit parallel light. The slide locks maintains theretinoscope in calibration when performing retinoscopy with diverging,converging or parallel retinoscopic light (as illustrated in FIGS.1-15). The retinoscopic technique for detecting AMD requires theretinoscope to emit parallel light rays from the same retinoscopicworking distance for each eye. The elongated head rest allows theexaminer to were his or her glasses.

Formula for Calibration of Retinoscope to Emit Parallel Light:

The formula for determining the focal length and power of the pupillaryimage of the retinoscope emitting parallel light is:Image I ₁+Image I ₃ =t(D) at emmetropiaImage I ₁=vergence of retinoscopic light (DImage I ₃=pupillary reflex (D)t(D)=RWD expressed in dioptersSince the vergence of parallel light (Image I₁) is 0.00 D, the pupillaryreflex is equal to the retinoscopic working distance (cm) expressed indiopters.Image I ₃ =t(D) at emmetropiaUpon neutralization of the patient's refractive error and thefulfillment of the examiner's retinoscopic requirements, conjugate oridentical images are formed in the patient's and an examiner's eyes.Requirements for Examiner to See Conjugate Images of the ReflectedPupillary Streak (Image I₃)

-   -   1. The examiner's refractive error must be corrected.    -   2. If the retinoscopist is presbyopic, a spherical lens with a        focal length equal to the retinoscopic working distance attached        to the back of the retinoscope will produce a clear image of the        pupillary streak.    -   3. The retinoscopic working distance must be the same for the        right and left eyes.    -   4. The patient's right eye must be examined by the        retinoscopist's right eye and vice versa.    -   5. The evaluation of the diagnostic pupillary streak requires an        8-10° off-axis retinoscopic position, laterally displaced. This        allows the patient to fixate on the Snellen letters, reduces        accommodation and maintains central fixation. An 8-10° off-axis        position requires the retinoscope to be displaced 4 cm laterally        to the patient's pupil for a 60-65 cm retinoscopic working        distance.    -   6. The highest concentration of pigment of located in the fovea.        The foveal pigment decreases precipitously by a factor of 1/300,        7-8° from the fovea axis to the periphery of the retina        (Beatty). A decrease in the 8-10° off axis reflectance of the        pupillary reflex as compared to on-axis retinoscopy is more        indicative of RPE damage and loss of melanin pigment of the        retinal pigment epithelium.    -   7. A 3-4 mm undilated pupil produces the optimal conjugate        pupillary reflex. A dilated pupil induces higher order        aberrations blurring the optical qualities of the pupillary        streak. A dilated pupil will induce aberrant astigmatic error in        the pupillary reflex, especially in the vertical meridian.        Calibration of Retinoscope to Emit Parallel Light Rays:    -   1. Move the thumb-slide to focus the retinoscopic light through        a spherical lens onto a wall displaced the focal length of the        sphere from the wall. Adjacent slide bars 51 and 56 to keep        retinoscope calibrated emitting light.    -   2. Align the arrow head of the “parallel calibration line” Ξ        symbol on the calibration plate or the attachable Ξ emblem in        FIG. 21 with the circumferential calibration line above the        knurl to mark the position of the power capsule housing the bulb        for future parallel infinity retinoscopies.    -   4. Attach calibration plate to the side of the retinoscope, as        illustrated in FIG. 21.    -   5. Adjust the slide-bar to maintain the thumb-slide in a fixed        position to maintain the calibration of the retinoscope for        future diagnostic parallel and converging or diverging        retinoscopies, as illustrated in FIG. 19B-E. The thumb-slide and        slide bars allows one to change the vergence of the retinoscopic        light from converging or diverging retinoscopy to parallel        without moving the retinoscope or changing the retinoscopic        working distance.

The luminance of the calibrated pupillary streak is graded on a scale of1-5, as illustrated in FIG. 22, to evaluate the severity of theage-related maculopathy or degeneration (AMD) and other maculopathies.

It is to be understood that while a preferred embodiment of theinvention is illustrated, it is not to be limited to the specific formor arrangement of parts herein described and shown. It will be apparentto those skilled in the art that various changes may be made withoutdeparting from the scope of the invention and the invention is not to beconsidered limited to what is shown and described in the specificationand drawings.

Having thus described my invention, I claim:
 1. A calibration plate forcalibrating a retinoscope for detecting age-related maculopathies, saidretinoscope having a handle, a lamp houses within a power capsule with acalibration line located thereon, a lens located above the lamp and athumb-slide for sliding the power capsule housing the lamp, saidcalibration plate comprising: a flat piece of material having a frontsurface and a rear surface; at least one calibration line located on thefront surface; an attachment means for attaching said calibration plateto a side portion of the retinoscope; said calibration plate beingcapable of sliding up or down via an adjustment means that allows a userto adjust the calibration plate on the retinoscope so that the parallelcalibration line located on the front surface of the calibration plateis in alignment with the calibration line located on the power capsule;and said calibration line is located at a predetermined position on thecalibration plate to allow for alignment with the calibration line onthe power capsule for calibrating the retinoscope for a pupillary reflexequal to the retinoscopic distance using parallel retinoscopic light. 2.The calibration plate of claim 1 further comprising: slide bars attachedto the retinoscope and located superiorly and inferiorly to thethumb-slide via the attachment means; said slide bars being capable ofsliding up or down via the adjustment means that allows a user toposition a bottom edge of the superior slide bar at a predeterminedlocation above the thumb-slide to prevent the thumb-slide from movinghigher than the bottom edge of the superior slide bar and to positionthe top edge of the inferior slide bar at a predetermined location belowthe thumb slide to prevent the thumb slide from moving lower than thetop edge of the inferior slide bar.
 3. The calibration plate in claim 1wherein: said parallel calibration line is aligned with the calibrationline on the power capsule for calibrating the retinoscope emittingparallel retinoscopic light.
 4. A method for calibrating a retinoscopefor detecting age-related maculopathies, said retinoscope having ahandle, a lamp housed within a power capsule with a calibration linelocated thereon, a lens located above the lamp, a thumb-slide forsliding the power capsule housing the lamp up or down, a calibrationplate slidably attached to a side portion of the retinoscope proximateto the thumb-slide, said calibration plate being constructed from a flatpiece of material having a front surface and a rear surface with atleast one parallel calibration line located on the front surface; saidmethod comprising the following steps of: a. measuring one'sretinoscopic working distance using the retinoscope; b. calibrating theretinoscope to emit parallel light rays; c. aligning the parallelcalibration line on the calibration plate with the calibration line onthe power capsule; and d. placing retinscope calibrated to emit parallellight rays at one measured retinoscopic working distance.
 5. The methodof claim 4 wherein: said retinoscopic light is a parallel retinoscopiclight.
 6. The method of claim 4 wherein: A head rest of the retinoscopeis elongated to allow an examiner to were glasses while using theretinoscope.
 7. The method of claim 4 wherein: maculapothies of the eyeare detected.
 8. The method of claim 4 wherein: cystoid macular edemapost cataract surgery is detected.